Mitsubishi MELSEC QJ71C24, User Manual

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MELSEC-Q
7 DATA COMMUNICATION USING THE BIDIRECTIONAL PROTOCOL
7.3 Processing when Simultaneous Transmission Performed During Full-Duplex
Communications
This section explains the processing when simultaneous transmissions occur in full-
duplex communication.
7.3.1 Processing when simultaneous transmissions occur
This section explains the processing performed by the Q series C24 when the external
device and the Q series C24 transmit at the same time during data communications
using the bidirectional protocol.
Since the external device and the Q series C24 do not transmit at the same time
during half-duplex communications (see User's Manual (Application)), this section does
not have to be read.
When an external device and the Q series C24 transmit at the same time, the Q series C24
processing depends on the setting of "Simultaneous transmission data valid/invalid
designation" with GX Configurator-SC.
The GX Configurator-SC setting value, "Simultaneous transmission data valid/invalid
designation" is stored in the following areas of the buffer memory.
Simultaneous transmission data valid/invalid designation (addresses: 9B
H
/13B
H
)
The Q series C24 communication data processing for each setting is described in
Section 7.3.2.
Q series C24 processing contents
Setting contents
with GX Configurator-SC
Value set to buffer
memory
(Address 9B
H
/13B
H
)
Message transmit processing Message receive processing
Transmission data: Valid
Receive data: Valid
0000
H
Waits to receive the response message (1)-2)
while checking time-out after data
transmission (1)-1) is complete.
Posts normal end or abnormal end according
to whether or not the programmable controller
CPU received a response message through
the buffer memory. Transmits a response message (2)-2)
after data reception (2)-1) is complete.
Posts the receive data and receive
result to the programmable controller
CPU through the buffer memory.
Transmission data: Invalid
Receive data: Valid
0100
H
Posts a simultaneous transmission error to
the programmable controller CPU through the
buffer memory after data transmission (1)-1).
Does not wait for a response massage (1)-2) in
reply to data transmission (1)-1). Transmits a response message (2)-2)
after data reception (2)-1) is complete.
Posts the receive data and receive
result to the programmable controller
CPU through the buffer memory.
Transmission data: Valid
Receive data: Invalid
0001
H
Waits to receive the response message (1)-2)
while checking time-out after data
transmission (1)-1) is complete.
Posts normal end or abnormal end according
to whether or not the programmable controller
CPU received a response message through
the buffer memory. Ignores data reception (2)-1) and
discards the received data.
Does not transmit a response message
(2)-2).
Does not inform the programmable
controller CPU that data was received.
Transmission data: Invalid
Receive data: Invalid
0101
H
Posts a simultaneous transmission error to
the programmable controller CPU through the
buffer memory after data transmission (1)-1).
Does not wait to a response massage (1)-2) in
reply to data transmission (1)-1). Ignored data reception (2)-1) and
discards the receive data.
Does not transmit a response message
(2)-2).
Does not inform the programmable
controller CPU that data was received.
( )-m) is the number showing the correspondence with the messages in the illustration shown in Section 7.3.2.